EMC2301 Standard Microsystems Corp., EMC2301 Datasheet - Page 24

• Manufacturer Part Number: EMC2301
• Description: Rpm-based Pwm Fan Controller
• Manufacturer: Standard Microsystems Corp.

Revision 1.2 (03-22-10)
5.1.1
ADDR
FDh
3Ah
3Bh
3Ch
3Dh
3Eh
3Fh
FEh
FFh
36h
37h
38h
39h
EF
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R
R
R
R
During Power-On-Reset (POR), the default values are stored in the registers. A POR is initiated when
power is first applied to the part and the voltage on the VDD supply surpasses the POR level as
specified in the electrical characteristics. Any reads to undefined registers will return 00h. Writes to
undefined registers will not have an effect.
Lock Entries
The Lock Column describes the locking mechanism, if any, used for individual registers. All SWL
registers are Software Locked and therefore made read-only when the LOCK bit is set.
TACH Target High
TACH Target Low
Fan Valid TACH
Manufacturer ID
Band High Byte
Band Low Byte
TACH Reading
TACH Reading
Fan Max Step
Fan Drive Fail
Fan Drive Fail
Software Lock
Fan Minimum
Configuration
Fan Spin Up
REGISTER
Product ID
High Byte
Low Byte
Revision
NAME
Count
Drive
Byte
Byte
Table 5.1 EMC2301 Register Set (continued)
Stores the number of Tach counts used
Holds the target tachometer reading low
Holds the tachometer reading high byte
must match the target fan speed at full
to determine how the actual fan speed
Holds the tachometer reading low byte
Sets the maximum change per update
Sets the configuration values for Spin
Sets the minimum drive value for the
Holds the target tachometer reading
Holds the tachometer reading that
indicates Fan is spinning properly
Stores the unique Product ID
Up Routine of the Fan driver
Stores the Manufacturer ID
Locks all SWL registers
Revision Registers
high byte for the Fan
DATASHEET
for the Fan driver
Lock Register
byte for the Fan
FUNCTION
for the Fan
for the Fan
scale drive
Fan driver
Revision
24
DEFAULT
VALUE
(40%)
5Dh
19h
10h
66h
F5h
00h
00h
F8h
FFh
FFh
F8h
00h
37h
80h
RPM-Based PWM Fan Controller
LOCK
SWL
SWL
SWL
SWL
SWL
SWL
SWL
No
No
No
No
No
No
No
SMSC EMC2301
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Datasheet
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